Question

Which of the following is a deuterostome?
A. Snail
B. Octopus
C. Sea star
D. Earthworm

Answer 1

Hint: As we knew that, earthworm is a reddish-brown terrestrial invertebrate that inhabits the upper layer of the moist soil. During day time, they live inside the burrows made by boring and swallowing the soil. In gardens, they have long cylindrical bodies. The body is divided into more than hundred segments, but the deuterostome belongs to animals like echinoderms.

Compete answer:
Option A: Snail- Snails are born with no appendages. They belong to phylum Mollusca. They usually are slow walkers as they lack any legs.
Option A is not the correct answer.
Option B: Octopus- Octopus are aquatic animals which have many appendages with no body and a big protruded head. They are from phylum-Mollusca.
Option B is not the correct answer.
Option C: Sea star- Sea star is also called as sea urchins which belong to phylum Echinodermata. Echinodermata is called a deuterostome.
Option C is the correct answer.
Option D: Earthworm- Earthworms have thorax which consists of three segments called-the prothorax, mesothorax and metathorax. Each segment has a pair of short legs. Thorax is the region between the abdomen inferiorly and the root of the neck superiorly. It forms the thoracic wall, its superficial structures and the thoracic cavity.
Option D is not the correct answer.

Therefore, Option C is the correct answer.

Note:
As we discussed, the sea star is a deuterostome. Earthworms are also known as friends of farmers because they make burrows in the soil and make the soil porous which helps in respiration and penetration of the developing plant roots. They are also used as bait in catching fishes. The process of increasing fertility of soil is known as Vermicomposting.